relative to itself. it becomes the event observer. since this is all hypothetical, and not to get lost in the sauce, I think it would be more fun to re-imagine it within the context of the timechain.
We can build models that can track + predict movement. like watch gears, each layer adds on another complexity. eventually covering the movements of everything. this could provide two things:
  • give us a reference for positioning: of ourselves, in reference to our planet, in reference to our solar system, in reference to our galaxy, and so on - in time.
  • give us a reference for time: like you said, we can not trust using the sun and our relations to it as a reference of time/space. there is no aug 28 2024 in space, and if history did not play out the way it did, we could be using another calendar with other dates. But we can use the reference for positioning to extrapolate a reference for time. since the the universe is expanding all the time, it should keep positions unique enough for no overlaps in time.
i give you the timespacechain.
disclaimer: i just woke up, need coffee.